1. Field of the Invention
The present invention relates to a camera adaptor for a medical-optical observation instrument, in particular for a surgical microscope. In addition, the present invention relates to a combination of a camera adaptor and a camera.
2. Description of the Related Art
So-called phototubes are often available in research microscopes for photographic or video-technical recording of an observation object. In the case of a stereoscopic microscope, there then is, for example, a third connecting piece to which a camera housing without a camera objective is generally connected, in addition to the two eyepiece connecting pieces. However, DE 200 10 121 U1 has also disclosed camera adaptors, which have an attachment apparatus for a camera and allow the use of a camera with an objective on the photo connecting piece. If there is no phototube on the microscope, it is possible to use a camera adaptor as described in US 2001/0048549 A1 for connecting a camera to an eyepiece connecting piece of an eyepiece tube.
The two aforementioned variants for connecting a photo camera or video camera to a microscope are however generally not suitable for connecting a camera to a surgical microscope. This is because a medical practitioner using the surgical microscope should be impeded as little as possible by a camera. Furthermore, in a surgical microscope, it is not always straightforwardly possible to arrange a decoupling apparatus for the phototube in the binocular beam path of the observer. By way of example, microsurgery often uses moveable tubes, so-called swivel tubes, to be able to ergonomically adapt a surgical microscope to the surgical situation. The use of a decoupling device in the binocular tube is not possible in swivel tubes.
The use of a camera at an eyepiece connecting piece of the stereo tube of the surgical microscope is excluded from the outset because the medical practitioner requires both eyepiece stages during an operation and thus no such eyepiece connecting piece is available for attaching a camera. Therefore, in surgical microscopes, the decoupling device with a camera connecting piece is situated in the region of the parallel beam path between the magnification changer and the binocular tube. Adaptors provided with an additional optical system, which allows the object observed by the microscope to be imaged on the camera chip, are then attached to such an output. Such an output for connecting a camera and corresponding adaptors are described in, for example, U.S. Pat. No. 5,835,266 and U.S. Pat. No. 5,264,928. Adaptors for use at such camera outputs of a surgical microscope are moreover described in US 2008/0152337 A1 and WO 01/799 10 A1. The described adaptors have angled optical systems with a mirror or a prism within the adaptor optical system, with the aid of which the image is displayed the right way up and the right way round on the image sensor of the camera. The display being the right way up and the right way round is important, particularly in the case of video recordings shown to an assistant or other auxiliary staff during the operation, because the display being the right way up and the right way round is of essential importance to the surgical staff.
Although the camera adaptor as per U.S. Pat. No. 5,264,928 also comprises a non-angled beam path, the latter is only provided for connecting a photo camera. Images of a photo camera, which are without current importance to the treating medical practitioner or the auxiliary staff during the operation, do not however require an illustration of the operation site that is the right way up and the right way round. By contrast, the video camera in U.S. Pat. No. 5,264,928 is also attached to the camera adaptor via an angled beam path.
The camera adaptors with angled optical systems have a large installation volume and many optical elements. Moreover, the assembly and adjustment thereof is complicated and it is extremely difficult to attain a sufficiently high image quality in the adaptor optical system.
It is therefore an object of the present invention to provide a camera adaptor for a medical-optical observation instrument, which is particularly suitable for connecting a video camera, has a small installation volume and can be implemented with a sufficiently high image quality of the adaptor arrangement. A further object of the present invention is to provide an advantageous camera-adaptor combination for a medical observation instrument.